After Sonic the Hedgehog (2006) tried to revive the Sonic Adventure formula and was met with negative critical reaction, Sega decided to take a step back and think more carefully about the next game in the franchise. Borrowing well-received elements from Sonic and the Secret Rings and Sonic Rush, Sonic Unleashed frequently shifts between a classic side-scrolling perspective and a behind-the-back 3D perspective in an attempt to provide the best of both worlds. In general, Sonic Unleashed features a tighter, much more narrowly focused design when it comes to Sonic's standard ''high speed'' gameplay.
Like Sonic Adventure and Sonic the Hedgehog, Unleashed is broken up between two specific modes: Towns and Action Stages. Towns advance the game's storyline and house NPC characters (which offer side missions or items to Sonic) and generally lead the player to access the next level (an Action Stage) via that town's "Gaia Gate". In the PS3/360 Sonic Unleashed, new stages are accessed by collecting Sun and Moon Medals hidden within stages and towns, whereas in Sonic Unleashed for PS2/Wii, Sun and Moon medals are awarded strictly by completing stages. In comparison to past Sonic games, the towns in Sonic Unleashed for PS3/360 are considerably more compact in size and generally can be navigated from end to end in a matter of seconds. However, the Gaia Gates in the PS3/360 Sonic Unleashed, while compact in size, can be immensely confusing to navigate while also being unclear in presenting the player with their next objective to progress through the game.
The Action/Town stage motif is further broken down by what time of day they're accessed. While the sun is out, players are given control of Sonic the Hedgehog, who is equipped with the ability to boost, drift, homing attack, leg stomp, wall kick, and quick-step (a strafing maneuver). Once the sun sets and day turns to night, Sonic transforms into The Werehog, a shaggy beast who uses his claws to attack enemies and long stretchy arms for platforming. After defeating a certain number of enemies and charging up enough energy, the Werehog can "Unleash", making him move faster and hit harder, in addition to being invincible.
In Sonic Unleashed for PS3/360, things like defeating enemies, eating food, and completing certain side missions will earn Sonic experience points that he can use to upgrade his abilities. For Sonic the Hedgehog, Speed and Ring Energy can be upgraded, and for the Werehog, Strength, Combat, Health, Shield, and Unleash can be upgraded, and although the Werehog starts the game with only a small handful of attacks, by upgrading the "Combat" ability, over 30 combo attacks in total can eventually become available for the player to choose from. (In Sonic Unleashed for PS2/Wii, the amount of combo attacks available is much fewer.)
It seemed like another routine assault on Doctor Eggman's latest orbital space station: a showdown with a couple hundred robots, and a fight to the death with the Doctor himself in a giant mechanized suit of armor. As Sonic uses the Chaos Emeralds to transform in to Super Sonic to finish the job, Eggman flees the scene, retreating to his final stronghold.
When Super Sonic catches up with the fearful Doctor, Eggman suddenly slumps to his knees and pleads with the hedgehog to spare him. He swears to change, to reform and stop trying to take over the world. Sonic is a little taken aback at the whole situation; Eggman has never begged for mercy before. This was, unfortunately, exactly the reaction Doctor Eggman was looking for. Catching Sonic off guard, Eggman pushes a button mounted on a nearby console. Large metal prongs raise out of the floor, and suddenly, Super Sonic finds himself trapped inside of a force field. As the machine whirs to life, Sonic is paralyzed and the seven Chaos Emeralds are forcibly extracted from him, de-energizing his Super Sonic form. Laughing madly, Eggman pushes another button on the console, triggering his stronghold's true function: A massive laser cannon. With the magical power of the Chaos Emeralds a
t its disposal, the cannon fires directly at the planet below, piercing it straight to the core. As the planet shatters in to fragments from the force of the blow, a mysterious, ethereal creature raises from the depths. Luring Sonic here and releasing whatever was trapped inside the planet was part of Eggman's plan all along.
Sonic himself is not doing too good, though. Having never been forced out of Super Sonic like that before, his body transforms in a different way -- he grows massive claws, sharp teeth and long, shaggy hair. Just as he is able to gain his senses as to what is happening, Doctor Eggman gleefully ejects him out of the airlock to the ruined planet below, confident that he has finally won the day. As the transformed ''Werehog'', Sonic plummets toward the ground from space, thus beginning a new adventure to reunite the continents.
The game of Sonic Unleashed spans up to 9 distinct continents. But not all continents are available all of the time -- frequently the player will have to return to locations at specific times of day in order to progress forward in the game. For example, while the player visits the continent of Adabat during the night as the Werehog, they do not return there as Sonic in the day time until some time later.
Each continent featured in Sonic Unleashed generally has one town hub, one Gaia Gate hub, one main daytime stage act, and up to 4 main nighttime Werehog stage acts. In addition to those, a continent can have one or more more boss encounter (as either Sonic or Werehog), and any number of optional mini-acts to complete. (In Sonic Unleashed for PS2 / Wii, these additional acts are sometimes as long as the main stage.)
Note that Sonic Unleashed for PS3 / 360 also includes two Tornado shooting stages, which do not take place on any continent.
- Stage Name: Windmill Isle
- Based on Mykonos, Greece
- Stage Name: Rooftop Run
- Based on Western Europe
- Stage Name: Savannah Citadel
- Based on Northern Africa
- Stage Name: Dragon Road
- Based on China
- Stage Name: Cool Edge
- Based on Alaska and the Arctic Circle
- Stage Name: Arid Sands
- Based on the ruins of Petra, located in Southeast Asia.
- Stage Name: Skyscraper Scamper
- Based on New York City, USA
- Stage Name: Jungle Joyride
- Based on Thailand
- Stage Name: Crimson Carnival
Tomoya Ohtani, one of the soundtrack artists from Sonic the Hedgehog and Sonic Rush Adventure returns as lead composer on the soundtrack for this game along with Sonic musical veterans Kenichi Tokoi, Fumie Kumatani, Hideaki Kobayashi, Takahito Eguchi, and Mariko Nanba. Orchestrated tracks for the game were performed by the Tokyo Philharmonic Orchestra. The game contains two vocal tracks:
- "Endless Possibility" by Tomoya Ohtani, featuring vocals by Jaret Reddick of the band "Bowling for Soup".
- "Dear My Friend" by Mariko Nanba, performed by Brent Cash, with lyrics by Candie Y
Purported to be in development since 2005, Sonic Unleashed's "Hedgehog Engine" is a multi-purpose game engine developed by Sega as an alternative to engines like Unreal Engine 3, idTech5 and the Source Engine. At the time of its release, the Hedgehog Engine was most notable for two relatively cutting-edge features: the rapid speed in which it could load streamed texture data off of the disc (eliminating texture pop-in), and its ability to render Global Illumination lighting data.
Global Illumination is a term used to reference the act of light bouncing off of surfaces. For example, if sunlight streams in through an open window on to a green floor, green light will bounce outwards from that surface and cast the entire room in that color. Hedgehog Engine was one of the first game engines to display this type of lighting technology.
At the time of release, calculating pre-baked Global Illumination data for a single level in Sonic Unleashed would take a networked render farm of 100 computers an average of 2-3 days.
Differences Between Versions
Although Sonic Unleashed was released on four different platforms, two different versions of the game exist: the "High-Def" version for the Xbox 360 and Playstation 3, developed by Sonic Team, and the "Standard-Def" version for the Playstation 2 and Nintendo Wii, co-developed by Dimps Corporation. Both versions of the game follow roughly the same story, but feature significant differences:
- All of the story-critical events in the Standard-Def version are pre-rendered videos of the High-Def version's real-time cutscenes.
- In the High-Def version of Sonic Unleashed, you must physically traverse towns on foot as Sonic or the Werehog. In the Standard-Def version, towns are relegated to a menu where you select different locations in the area in order to visit them and talk to characters.
- Most NPCs you meet in the High-Def version of Sonic Unleashed can be ignored as you find your way around to the next story beat. In the Standard-Def version, you must click on every location on the map menu and talk to every NPC before progressing forward.
- In the High-Def version of Sonic Unleashed, NPCs can offer optional side missions in order to flesh out the story. None of the NPCs in the Standard-Def version have side missions.
- The player eventually unlocks the ability to use a camera in the High-Def version of Sonic Unleashed, which can be used to exercise evil spirits from possessed NPCs. This mechanic is not present in the Standard-Def version.
- Sun and Moon medals are available to collect in each version of the game. In the High-Def version, medals must be found and collected within towns and levels themselves and are used to open new levels as you progress through the game. In the Standard-Def version, medals are awarded for getting high ranks on levels and are used to unlock bonus content.
- "Gaia Gate" sections vary between the two versions: High-Def Gaia Gates are smaller, open areas with enemies and rings where you can find new equippable gear and visit level entrances. Standard-Def Gaia Gates are stone temple areas that only contain level entrances, opened by using keys collected through talking to NPCs in the Town Menu.
- Bonus levels can be discovered by exploring the High-Def version's Gaia Gates. Similar bonus levels are available in the Standard-Def version, but are available from a menu, and are unlocked as you collect medals or reach other progression milestones.
- Two continents were altered for the Standard-Def version of the game: Though you visit Mazuri to fight the Egg Beetle Boss, its associated level "Savannah Citadel" is not present in the Standard-Def version, and you never visit Empire City for any reason whatsoever.
- In the High-Def version, Sonic gets one continuous "boost" meter that can be permanently extended by spending experience points earned over the course of the game. In the Standard-Def version, the boost meter is broken down in to segments, with each boost expending one individual segment. The boost meter in the Standard-Def version is temporarily extended by collecting rings in each level, and gets reset after the stage is clear.
- Sonic's controls are a little more stiff in the Standard-Def version of the game, offering less fluidity but tighter steering.
- Though a single Werehog level in the High-Def version of the game can last for 15-20 minutes or more, Werehog levels in the Standard-Def version are broken in to four shorter (7-10 minute) sub-levels that are all played one right after another.
- In the High-Def version, the Werehog can run when the player holds down a button. In the Standard-Def version, running is initiated by double tapping a direction on the analog stick. While running, the Werehog is also a little more slippery in the Standard-Def version.
- If playing on the Nintendo Wii for the Standard-Def version, the Werehog's attacks can be executed using Motion Control Gestures.
- In the High-Def version, players earn experience points via yellow gems dropped from defeated enemies. Experience can be spent to either level up Sonic or the Werehog's different stats. Sonic's stats improve his Max Speed and Boost meter. The Werehog's stats include improving his Life, Strength, Unleash meter, Shield meter, and Combat ability. In the Standard-Def version, only the Werehog can be upgraded, and experience points are spent automatically, with level-ups improving its stats without any choice from the player.
- In the High-Def version, spending experience to upgrade the Werehog's "Combat Ability" will unlock 31 different special moves and combos to use during fights. In the Standard-Def version, there are only five of these special moves.
- In both versions of the game, the player is awarded a "Rank" at the end of a stage based on their skill. In the High-Def version, Rank is measured based on a player's score, which includes a number of bonuses for finishing levels quickly, grabbing a lot of rings, defeating enemies and executing QTE segments correctly. In the Standard-Def version, a player's rank is measured only based on how quickly the level is completed.
Night of the Werehog
Near the launch of Sonic Unleashed, Sega celebrated the launch of "Sega Sammy Visual Entertainment", an animation studio opened not only to create high-quality CGI for Sega games, but to produce feature-length movies. In addition to animating all of the CGI for Sonic Unleashed, Sega Sammy V.E. produced an 11 minute short film titled "SONIC: NIGHT OF THE WEREHOG". In it, Sonic and Chip are caught in a rainstorm and take shelter in what looks to be an old abandoned mansion.
Unknown to them, a trio of ghosts haunt its halls - two of the specters are armed with cameras and compete for the affection of a lady ghost by snapping photos of their victim's frightened expressions, which she finds amusing. Though Chip is easily scared and makes for easy pickings by the ghosts, as they move in and attempt to scare Sonic, the ghosts are surprised when the storm breaks to reveal a full moon - causing Sonic to transform in to the snarling Werehog. Undeterred, their efforts to humiliate Sonic eventually devolve in to a knock-down drag out fight for supremacy. The two photographer ghosts from Night of the Werehog actually make cameo appearances in Sonic Unleashed, in the side-missions "Tower Terror" and "Fright Fight". In 2010, "Sega Sammy Visual Entertainment" was renamed to "Marza Animation Planet", where they underwent their first feature-length movie project: a CGI adaptation of the anime "Space Pirate Captain Harlock".
- The longest level in Sonic Unleashed clocks in at over 16 square miles.
- Early builds of the game called all the levels their real-world equivalents. For example, Apotos was originally listed as "Mykonos, Greece".
- The Japanese versions of Sonic Unleashed for PS3/360 is called "Sonic World Adventure". The versions are nearly identical, except for one change: Mazuri's level, "Savannah Citadel" is renamed to "Clay Castle".
- On the North American box for the Xbox 360 version of Sonic Unleashed, an icon is listed for "Leaderboards". Sonic Unleashed contains no leaderboards, and all other versions of the game replace this icon with one for "Content Download".
- The music for "Savannah Citadel" during the day is actually a remix of a tune from Sonic the Hedgehog on the Master System used during the credits sequence.
- Similarly, the main orchestral song titled "The World Adventure" contains numerous similarities to the music used for Angel Island Zone in Sonic the Hedgehog 3.
- In the "Town" for the final location in the game (Eggmanland), players can find and talk to three of Dr. Eggman's Guard Robots, the Model Numbers of which are references to various Sonic games throughout the years: EF-MD1991, EF-DC1998 and EF-XB2006. EF-MD1991 is a reference to the release of Sonic the Hedgehog on the Mega Drive in 1991, EF-DC1998 being a reference to the release of Sonic Adventure on the Sega Dreamcast in 1998, and EF-XB2006 referencing SONIC the Hedgehog on the Xbox 360/PS3 in 2006.
- Once players talk to the three Guard Robots in Eggmanland, their character profiles are added to the game's Encyclopedia. EF-XB2006's character profile describes him as "lacking real world experience", likely a reference to SONIC the Hedgehog (2006)'s extremely poor critical reception. In similar fashion, EF-DC1998's description says that he was "Once a model mainstay of the Egg Fighter Force" but he has grown tired of working and now plays hookie to avoid his duties. This is potentially a reference to the fact that, prior to Sonic Unleashed, most 3D Sonic games were heavily based off of the ground work established by Sonic Adventure in 1998.
- Though never visible for more than a couple seconds at a time, it would appear that Dr. Eggman keeps a Dreamcast by his side wherever he goes, as any time you're afforded the ability to peek inside of his Eggmobile, it's always sitting next to him. Viewing the image in HD, it would appear he also carries two games with him: A never-released Sega Dreamcast version of NiGHTS: Journey of Dreams and a game apparently titled "Eggman Adventure", a parody of Sonic Adventure.